Archive for May, 2012

Photographing the sun with standard photographic equipment

The sun, the giver of life on this planet and so important to photography. It provides the natural light photographers crave after but it’s a subject in itself that few other than astrophotographers ever attempt. Loads of people will have a crack at photographing the moon but few will take on the dangers of the sun but it’s not as hard as you might think even with some standard photographic equipment.

Of course, using a telescope with a solar film filter or a dedicated solar scope will provide the best results but you can still capture those sunspots with possibly, what you have already.

Before we proceed though, a warning. Photographing the sun is dangerous, I cannot stress this enough. Blindness can occur in seconds and photographic equipment can be ruined just as quickly but proceeding with some caution you can minimise risks and catch pictures of the surface of the closest star to Earth. I accept no responsibility for any lack of sight or melted cameras that may result from the following, you try this at your own risk.

OK? Not freaked you out? Let’s get started!

Firstly you will need:

DSLR camera (preferably)
As big a lens as you have (I use a Sigma 70-200mm f2.8 and 2x tele giving 400mm)
Tripod
At least one 10 stop photographic filter or enough filtration to get as much as 10 stops.

The 10 stop filter is essential. If you don’t have one, can’t get access to one or can’t replicate with other filters DO NOT proceed. Some filter sets come with 3 standard ND filters, 0.9, 0.6 and 0.3 which stacked will give you 6 stops, which is NOT ENOUGH but if you can add others in there to get to 10 stops on you go.

For extra safety I like to shoot with the DSLR tethered to my MacBook pro using the Nikon only Sofortbild software to control the camera but you can get away with a standard remote control on the camera, it’s just not quite as easy.

To get started, mount your camera on the tripod and add the 10 stop filter to the lens, set your focus to infinity and using the live view feature on your camera or laptop preview, locate the sun. Once you have it, cover the lens to stop heat build up. Now, switch on Exposure delay mode if your camera has it, close the lens up as much as you can, f22 or higher, I use f32 on my own setup. You should be in manual exposure mode, so set your exposure to as high as it will go, typically around 1/4000th and your ISO as low as it will go, typically ISO100.

Now, you’re good to go, uncover the lens, take the shot and cover the lens again. Now you can check what you have. You should have a white-ish disc, sunlight is white not yellow and if sunspots are visible then there will be darker areas on the disc. From here you can adjust exposure to get the best possible shot but DO NOT exposure for any length of time, keep the exposures in the region of thousandths on seconds, you do not need to go any higher at all.

If no sunspots are visible it may be that the side of the sun facing us has no activity on it at the moment, check http://www.space-weather.com for an up to date listing of active visible sunspots. If there are sunspots and you cannot see them on the shot you may be overexposing, dial in a faster shutter or up the f setting to as high a number as it will go and try again.

All going well, this is what you should end up with:
Sun 28 April 2012

The darker dots are the sunspots. I’ve also added a little false colour to make the shot look a little more like what people expect the sun to be.

It’s possible using http://www.space-weather.com to identify the sunspots and label these up on your shot.

Solar disc 14 May 2012

Solar Disc 21 May 2012

That’s all there is to it, it’s not that difficult with some pretty normal bits of photo equipment and take the proper precautions and you’ll be fine. Do please remember though, never look at the sun through the camera viewfinder, even with the filter on place and never leave your camera focused on it for long periods of time. Have some respect for the subject and you’ll be fine and get a shot of something not that many ever attempt.


This astro stuff DOES get easier, slightly…

Equatorial mounts, Newtonian reflectors, refractors, registax, counterweights, polar alignment, autostakkert, wavelets, webcams, tracking motors, collimation, Saturn, Venus, avi’s, sharpcap… Astro photography, it’s enough to put you off just thinking about the bewildering array of stuff to learn. What the hell are those things, where are they, what do they do, how do I use them? Well, with a little perseverance it DOES get a bit easier.

Take the telescope and mount to start with. When I first got it I had no idea what I was doing, Even now the EQ5 mount seems more like an instrument of mental torture than something to mount a telescope on but I am getting used to how it works. I’ve never attempted an accurate polar alignment yet mainly due to how late it is in summer until I can see Polaris but even a rough alignment is enough to get you moving. Simply set your latitude on the mount, 55 degrees for Edinburgh point the North leg funnily enough North and make sure the mount is level. It’s not perfect but it’ll allow you a go at some planetary imaging at least.

Just doing the above steps I’ve found that it’s adequate enough to keep a planet in the field of view for ages with the tracking motors engaged. It wouldn’t be any use at all for imaging deep space objects but for now, for planets and moon its working ok.

The tracking motors too came with the vaguest of instructions, now though I’m confident enough to find my target, lock the clutches and start the tracking and it works fine.

So, as I’d got hold of a Philips SPC900 webcam, all ready to be used with the scope and the skies had cleared it was time to give this planetary imaging a shot.

There’s not a lot of targets at this time of year, Venus is rapidly heading for its appointment with the Sun in June and Jupiter is long gone is the twilight sky. Saturn is getting higher and Mars to be honest has never been my favourite subject so Venus and Saturn were to be the targets.

When I setup, only Venus was visible in a still twilight sky. I can’t wait till dark as it’ll be lost behind the neighbourhood roofs. It’s so easy to locate in a twilight sky and the crescent shape is very visible in the scope and it’s quite a thin crescent now too. After centering Venus in the eyepiece I slipped in the 2x Barlow and made sure it was centered and then switched to the webcam.

Luckily for me, Venus was still there with the webcam and using the free capture software, SharpCap I was able to get it centered on the camera and adjust the settings till I got a clear view. I got a couple of short captures with the webcam until Venus was lost to the shed roof. I then ran the avi file through another free bit of software, Autostakkert which stacked the best frames from the movie.

The resulting image was saved as a TIFF and then opened in Registax 6 where you can adjust the wavelets. I have no idea what a wavelet is but it certainly works and greatly brings out the image detail and sharpness. I then finally opened the image in Photoshop CS5 for some final tweaks and this was the end result.
Venus 19 May 2012 Cropped

A million times better than I’ve managed with the DSLR, the webcams much smaller sensor gives a much bigger final image which in turn lets you get more detail. Using a webcam also lets you capture those microseconds of clarity through the atmosphere where the viewing is at its clearest and the stacking software puts all these together to get your final image. It takes a bit of getting your head around but it does work!

Saturn was next up and this was the AVI file I processed to get to the final image:

It’s probably way too long but after processing this in the same way as the Venus image I got to this final shot.

Saturn 19 May 2012

Which is a vast improvement on my best with the D90 attached to the telescope:

Saturn

As you can see, there’s a lot more detail in the stacked image, some colour too.

For a first shot with this style of imaging I’m pretty pleased especially as the seeing was pretty bad. There’s a lot of room for improving especially with the software end all of which I’ve hardly even scratched the surface of yet. I also need to get hold of a quality 5x Barlow lens to get a larger image. Lots to do, I just a few more clear nights!


Is it a bird? Is it a plane? No, it’s SUPERMOON!

Supermoon fever seemed to grip the online communities on Saturday night. Twitter was buzzing with it as people who would normally pay no interest in our nearest celestial neighbour peered upwards trying to see if the moon was indeed 14% bigger than usual and 30% brighter as the news websites reported. Of course if you hadn’t seen the moon for a few months then suddenly caught it on Saturday it would have looked different, if you look for it all the time you didn’t see much since the move to a big moon is gradual and not all at once.

The Supermoon, or perigee moon, is not a once in a lifetime occurrence as the media would have us believe, it actually happens a few times a year as the moon’s orbit gets closer to Earth and then ebbs away again, it’s just some are closer than others, this year’s wasn’t as close as the March one last year but it was still impressive.

With the moon’s latest close approach to Earth the timing wasn’t great with regards to the moonrise time still falling in daylight. The moon came up over the horizon from Edinburgh at 20.37 and to that ends I was stood on Blackford Hill with a good view to the South East with a Nikon D7000, Sigma 200mm f2.8, 2xtele and photographic tripod and the MacBook pro so I could try some tethered shots. However, as with all good astro plans the weather got in the way dumping a low bank of cloud on the horizon spoiling the fun. The sky was still very light too so gave up and went home in a huff.

It didn’t take too long though for the moon to get over that cloud bank and around an hour after moonrise I got my first shot at it from home. Sadly, it was so low I had to shoot from the front garden in-between passing Lothian Buses double deckers and glaring sodium streetlights. This was shot tethered to the MacBook pro with Sofortbild which lets you get a real handle on the focus, the golden glow of the low moon still very evident.

Supermoon 5th May 2012

Remember those buses I had to try and avoid, I didn’t manage it every time…

About an hour later with the moon higher in the sky I tried again, not tethered this time due to where I had to stand to get the shot (half way up the neighbours stair to avoid a telephone cable). The golden glow has lessened but there’s more contrast and detail.

Supermoon 2 5th May 2012

It might have just been imagination but even at midnight the sky still looked almost twilight to the south with that moon shining so brightly.

The following night with a later moon rise and more cloud about I wasn’t hopeful of anything at all but it did peek out from between the houses over the road very low down and very orange. Pretty impressive even though it wasn’t a “Supermoon” any longer.

Not quite so supermoon

The reality here is that any phase of the moon, near or far is a delight to photograph. Despite it being the same subject it’s a challenging subject to get right and atmospherics and cloud play their part too. It’s probably my favourite photographic object and it’s not out of reach for those even with basic photographic equipment. Supermoon or not, give it a try on the next clear day, daylight, twilight or night time it’s always worth a go.


First time photography with a telescope

After only a mere 3 days of frustration of owning a telescope and not being able to use it for the purpose it was designed, I finally got a clear night to try out a bit of photography with my newest photography acquisition, my Skywatcher Explorer 200P on an EQ5 mount.

With a clear sky looking almost certain the hardest part of waiting till it was dark enough to actually see anything in the night sky on Friday night. The moon was coming up frustratingly low and was steadfastly refusing to peek over the top of the house from my back garden so I was forced to wait until the sun had at least waved goodbye for the day.

While still in a twilight sky I obviously couldn’t properly polar align, not that in a dark sky I’d probably have had any more luck either if I’m honest! I did make an attempt though, first finding north using the iPhone compass, so it was probably east or something knowing the accuracy of the iPhone compass and I did level out the mount properly too. With this being the best I could do in a twilight sky I made an attempt at balancing the telescope and that was me ready to go.

I’d spent time earlier in the day setting up the finder scope so with Venus bright in the sky that where I headed. Centred nicely in the finder scope I looked through the eyepiece to find… nothing at all. After some searching I did find Venus and even in the 20mm eyepiece it was a brilliant sight. The crescent clearly defined and even better, the tracking motors seemed to be keeping it in the field of view as well. So far so good.

With Venus in my sights I setup the MacBook pro and tethered it to my Nikon D90, fitted the t-ring and the 2x Barlow (which is needed to get the prime focus) and switched out the eyepiece for the camera and watched the scope drift off on a tangent with the extra weight fitted. Re-balancing and trying again finally I got Venus in the D90 viewfinder and switched the live view on the laptop. This gave me a chance to play with some settings and get a few shots, none of which I’d be willing to stick up online…

By this time Saturn had peeked over the top of the house so that’s where I headed next. Despite a glaring moon just below it the view wasn’t bad at all. Easy to find, find the roof and move up, Saturn was an awesome sight, the rings and some of the moons clearly defined in the eyepiece. With the tracking more or less working I got a good chance to try out some single frame shots of the ringed planet before youngest son walked into the 5m USB cable between the D90 and MacBook pro knocking everything out of line again.

This was the best I got of Saturn, not exactly epic but I was pleased enough for a first go.

Saturn

Next up was Mars which was… unexciting so I skipped Mars and went in search of the Moon which was still hiding around the front of the house. Moving the scope I got a view of the Moon and within mere milliseconds of getting it in the eyepiece I realised the importance of having a Moon filter. There’s no way you should be looking at a nearly full moon without one. I worried for a bit I had damaged my left eye, the black spot the Moon left in a field of vision a bit of a worry to be frank! Thankfully it subsided and I won’t be doing that again. I did however hook up the camera and use the live view to the laptop to focus and get a few shots, the best of which is below although I’m frustrated at the lack of sharpness in the shot.

Moon 4th May 2012

The list of questions and things to learn is still massive. Among these…

1. How can I get the whole moon in a single photograph with the camera, the 2x Barlow means only bits at a time and when I tried eyepiece projection the result was more like a lensbaby shot with selective focus!

2. How the hell do you find deep space objects without a GOTO? I’m really thinking I’ll need to invest in the SynScan controller soon.

3. The tracking motors SEEM to work but I’m not convinced, Skywatcher seem to be overly vague in their operation.

4. How the f**k do you balance a telescope for the eyepiece and camera without having to adjust where the scope sits on the rings?

5. Where the hell did all these eyepiece caps come from? As the night wore on I seemed to have more than I had places to fit them?

6. Why do I need a woolly hat, scarf and big jacket in May!

7. Why did I buy such a heavy unwieldy telescope in the first place!

These, and not doubt many more questions may or may not be answered in the coming months…


The Astrophotography learning curve begins…

I wouldn’t call what I’ve been doing up until know as “actual” astrophotography. Sure, I’ve been snapping away at all manner of astro related subjects, planets, moons, sun, star clusters, conjunctions, earthshine, aurora, milky way, ISS to name but a few but it’s all been done on a photographic tripod and with the restrictions that brings. Not that it hasn’t been highly enjoyable, it has and it was quite cool to get into this utilising the camera kit I already had but I really wanted to get deeper into the hobby.

With that in mind I started to seriously look at getting a telescope around February. What I found though was an utterly bewildering array of kit on offer that made my head spin every time I looked at it. I spent hour pouring over telescopes on Amazon having to go off and Google all manner of things. What the hell was an alt-az mount, en EQ mount, what’s the difference from an EQ2 to an EQ6, focal lengths, aperture, motor drives and what’s this? Using a webcam???

It was too much to take in initially and with a fear of buying crap I backed off and bought nothing. I put the thoughts of telescopes out my head totally and thought about getting hold of a Sigma 150-500mm lens instead. Coupled with the 2x it would make it a 1000mm lens and I’d have other uses for a lens that size but then by chance I spotted a 2nd hand Meade 4504 telescope on an EQ mount for £80 for sale locally.

The Meade was a disappointment and a revelation at the same time. When I got it home on closer inspection it had had a hard life. The mount wasn’t working properly; it couldn’t be locked in place at all. The motor drives didn’t function either but the OTA was fine. I couldn’t get the camera to focus with it either so I sold it on quickly. What it did do though was take my breath away when I simply used it for observing. From that first night when I properly used it and saw Jupiter and its moons, Saturn and the Orion nebula I knew I had to get something better.

It took another few months of research until I fully understood what I needed. I had a rough budget of £500 and had to get the best from that I could. Initial plans for a Skymax 127 Mak on a GOTO alt-az where discounted when I realised that the alt-az would be great for getting going fast but it would end up frustrating me. No, I had to do this right. It had to be a heavy EQ mount; it seemed pointless going for anything else if I was going to try this properly.

Finally I settled on a Skywatcher Explorer 200P, an 8″ Newtonian reflector sat on an EQ5 mount. It gave me a nice mixture of sturdy EQ mount and a decent sized telescope. At £400 it wasn’t cheap and the SynScan goto version would have bust the budget by a lot so I also got the Skywatcher dual drive motors for the EQ5, all in just under the £500 budget.


Not the best pic, I’ll get better soon but it gives the idea!

Setup, it’s huge and pretty heavy. It’s certainly not a scope you’ll drag out for a quick 5 minutes viewing but I’m safe in the knowledge I’ve got kit that’s capable, once I know how to use it, to deliver what I want. Coming into summer there wasn’t a worse time to buy such an item but I hope to use the next few light months to get to grips with the new toy, learn that EQ mount and get used to the software that goes with astrophotography so when the winter rolls in again I’m prepared and ready to really start learning to image properly.

I’m in this for the long term now, prepared for the fact that it’s going to be a long and at time frustrating learning curve but I’m looking forward to it. If Edinburgh ever clears a clear night again I might even get my first shot of the moon through a telescope.

Here’s a quick artists impression of how I expect the sky over Edinburgh to look for the foreseeable future…

Keep following this blog for the forthcoming astrophotography related highs and more likely lows!


Sigma and a tale of excellent service

When I bought my D7000 I swore I would never buy another Sigma lens. It’s not the best when you get a nice new camera body and find issues with your lenses working with it which will always be an issue with 3rd party manufacturers.

Curiously, my Sigma 70-200mm f2.8 EX HSM which is now over 10 years old worked perfectly. However I lost AF in live view on my 10-20mm superwide but that wasn’t something that bothered me as that lens is nearly always MF only and I rarely ever use live view either.

The big problems started with my 28-300mm which was seen by the camera but just didn’t function at all. In the end I sold the lens on as I wasn’t that keen on it anyway but the real issue came with my Sigma 105mm f2.8 EX DG macro. Now, I love this lens. Every summer I cast off the shackles of landscape photography and delve head on into the wonderful world of plants and insects with the macro lens. It’s used a lot. The problem was though that the D7000 simply refused to even see the lens.

To say this hacked me off was an understatement. Sure, I still had my D90 where it worked perfectly but this lens was less than 3 years old and didn’t work with the new kit. I was so hacked off by this that when I was looking for a new mid range lens I totally discounted any Sigma product and went the extra mile for a Nikon 18-200mm VRII as hey, it’s a Nikon lens, and it’ll work for ever no matter what body I buy in future. Sure, it’s expensive but it won’t ever be obsolete.

Luckily though, Sigma DG products come with a 3 year warranty. No problem, send back to Sigma with the proof of purchase and they’ll re-chip it. Problem. No proof of purchase. I had bought it nearly 3 years ago and had no idea where the receipt would be. I phoned Jessops as I had bought the lens along with my D90 there and they couldn’t help. I emailed Jessops customer service and they did manage to locate a duplicate copy for me but when it arrived the date on the receipt was the day they had ran off the copy, not the original date of purchase.

I emailed Sigma again, expressing my displeasure that a less than 3 year old lens wasn’t working and explaining the proof of purchase issue. I had an email back asking me to phone their service supervisor which I did. In the end Sigma, with no persuasion needed offered to re-chip the lens in an act of goodwill even with no proof of purchase, something they didn’t have to do.

The lens was sent recorded delivery to Sigma in the UK and in only 5 days over a weekend too it arrived back re-chipped and cleaned too. Stuck on the D7000 and it worked like a dream. So there you go, in this day and age when the consumer now expects to be shafted silly there are sill a few companies out there giving decent service. My faith in the Sigma brand is restored and I wouldn’t hesitate to buy Sigma again, I always felt they were better built than the more expensive Nikon lenses anyway.

Now, my less than 2 year old original iPad can’t run some apps and it cost more than the lens did. Wonder what Apple’s response would be if I asked them to upgrade it?